Effects of Heat Treatments on Steels for Bearing Applications

AISI 52 100, 440C, REX20, and Crucible CRU80 steel samples were exposed to 16 different heat treatments to vary the levels of retained austenite. Rockwell C hardness measurements, optical microscopy, and compression testing were used to compare the properties of the different steels.     

Determination of an image point on a surface based on a \pi plane-based algorithm

Constitutive models of particulate materials often rely on distances between the current stress state in stress space and various surfaces. Examples of these surfaces include the bounding surface and the dilatancy surface. This paper proposes a rigorous method for determination of distance to a surface in stress space. It starts by examining operations on stress variables defined in the $\pi $ plane. Algorithms for determination of an image point on a surface are then presented as a function of the location of the current stress state with respect to the surface. For points within the surface, the bisection method is used; otherwise, the secant method is used. The paper shows that implementation of the proposed algorithm locates the image point on a surface in stress space with accuracy and rigor, providing an accurate measure of the distance to the surface that can be used in hardening or flow rules.     

Application of lysine, taurine, disodium inosinate and disodium guanylate in fermented cooked sausages with 50% replacement of NaCl by KCl

The effects of 50% replacement of NaCl by KCl and addition of the amino acids lysine and taurine and the 5'-ribonucleotide disodium inosinate and disodium guanylate on some sensory and physicochemical parameters of fermented cooked sausages were evaluated. The partial replacement of NaCl by KCl did not alter the manufacturing process; however, defects in the sensory quality were detected. Lysine at a concentration of 0.313% and a mixture of taurine (750 mg/kg) with disodium inosinate (300 mg/kg) and disodium guanylate (300 mg/kg) reduced the sensory defects caused by KCl, allowing the fermented cooked sausages to be elaborated with reduced sodium content and high sensory quality.     

Metal polymers

Summary Styrene-co-ethyl methacrylate colloids were obtained by codeposition at 77 K of the monomers with several metals such as Pd, Au, Ag, Cu, Zn, Cd, Ga, In, Ge, Sn, Sb and Bi. The colloids were polymerized with different amounts of initiator (BPO) at 65°C for 3.5 h and a wide range of viscosity average molecular weights (M_V, 10⁴–10⁵ g/mol) were obtained depending upon the metal used. The metal colloid concentration and stability are reported. The medium particle size of In comonomer colloids was 49 å. The thermal stability and metal composition are also described. The copolymers are stable even at 310°C; Pd-poly(styrene-co-ethyl methacrylate) being the most stable. The metal content ranging between 0.11 and 3.76% w/w for the highest MW fraction and between 0.08 and 0.96% w/w for the lowest MW fraction. Copolymers with different colors were obtained depending on the metal used.     

The five factor model of personality and job performance in the European Community.

In 3 prior meta-analyses, the relationship between the Big Five factors of personality and job criteria was investigated. However, these meta-analyses showed different findings. Furthermore, these reviews included studies carried out only in the United States and Canada. This study reports meta-analytic research on the same topic but with studies conducted in the European Community, which were not included in the prior reviews. The results indicate that Conscientiousness and Emotional Stability are valid predictors across job criteria and occupational groups. The remaining factors are valid only for some criteria and for some occupational groups. Extraversion was a predictor for 2 occupations, and Openness and Agreeableness were valid predictors of training proficiency. These findings are consistent with M. R. Barrick and M. K. Mount (see record 1991-22928-001) and L. M. Hough et al (see record 1991-06268-001). Implications of the results for future research and the practice of personnel selection are suggested. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Growth hormone axis in cushing''s syndrome

This article reviews some recent studies on alcohol preference, dependence, metabolism and pharmacokinetics which were mainly carried out in our department. The inbred strains of mice with genetically different alcohol drinking behavior and alcohol animal model treated with the neurotoxins, 6-hydroxydopamine and 5,7-dihydroxytryptamine, are useful for a behavioral and pharmacological approach to evaluate the contribution of specific neural systems to alcohol, drug dependence mechanism and alcohol drinking behavior. The relations between alcohol preference and some physiological conditions are reviewed. On the drug-alcohol interaction, some drugs containing the chemical group = CHONO2, antimony and methamphetamine are addressed. This article also deals with recent topics in the pharmacokinetics and pharmacodynamics of alcohol. The dose-dependency of the alcohol elimination rate, the first-pass metabolism during alcohol drinking, and the pharmacodynamic model for describing pulse rate reaction to plasma acetaldehyde are discussed.     

MCNP simulation to optimise in-pile and shielding parts of the Portuguese SANS instrument

A Small Angle Neutron Scattering instrument is being installed at one end of the tangential beam tube of the Portuguese Research Reactor. The instrument is fed using a neutron scatterer positioned in the middle of the beam tube. The scatterer consists of circulating H2O contained in a hollow disc of Al. The in-pile shielding components and the shielding installed around the neutron selector have been the object of an MCNP simulation study. The quantities calculated were the neutron and gamma-ray fluxes in different positions, the energy deposited in the material by the neutron and gamma-ray fields, the material activation resulting from the neutron field and radiation doses at the exit wall of the shutter and around the shielding. The MCNP results are presented and compared with results of an analytical approach and with experimental data collected after installation.     

Effect of ionizing radiation on the properties of arc-induced long-period fiber gratings

We experimentally study the effect of ionizing radiation on the properties of long-period gratings fabricated in two pure-silica-core fibers with the arc-discharge technique. It is observed that the spectra of the gratings remain almost unchanged after being subjected to doses in excess of 0.5 MGy. The results also show that the gratings' temperature and strain sensitivities are not affected by gamma radiation.     

Thermal Decomposition of Diammonium Tetrachloroplatinate to form Platinum Nanoparticles and its Application as Electrodes

Pt nanoparticles were obtained via the thermal decomposition of (NH₄)₂[PtCl₄] (diammonium tetrachloroplatinate) by heating from room temperature to 760 °C. The thermal decomposition process was analyzed using thermogravimetric analysis (TGA) and differential thermal analysis (DTA), X-ray thermodiffraction and infrared spectroscopy. The size and structure of the platinum particles were analyzed using transmission electron microscopy (TEM). The electrochemical activity of Pt particles was assessed by cyclic voltammetry in 0.5 M H₂SO₄. The TGA and DTA results suggested that the thermal decomposition of the precursor proceeded in two stages: loss of NH₄Cl at ~300 °C, followed by loss of NH₄Cl and Cl₂ at ~372 °C. Metallic Pt particles were then produced at temperatures of 372 °C and above. At 760 °C, the mean ± SD size of the Pt particles was (4.1 ± 1.6) nm, as determined from TEM measurements. In cyclic voltammetry (CV) measurements, an electrode comprised of glassy carbon and Pt particles in 0.5 M H₂SO₄ exhibited behavior similar to that observed using a polycrystalline Pt electrode.